Surgical chair.



PATBNTED MAR. 8, 1904.

A MUDANNOLD SURGICAL CHAIR.

APPLIUATION FILED APR. 23, 1903.

2 shame-anam- 1.

N0 MODEL.

lwuwwbo c NH Q i;

LEEEEE A. McDannold 351; WW I Wilf No. 754,383. PATENTBD MAR. 8, 1904.

A. MODANNOLD- SURGICAL CHAIR.

APPLICATION FILED APR. 23, 1903. .NO MODEL. 2 SHEETS-SHEET 2.

F ig.5.

A. McDalinoId UNITE STATES Patented March 8, 1904.

PATENT OFFICE.

ALEXANDER McDANNOLD,'OF ST. LOUISQMISSOURI.

SURGICAL CHAIR.

SPECIFICATION forming part of Letters Patent No. 754,383, dated March 8, 1904.

Application filedApril 23, 1903.

pertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

The object of my invention is to provide a simple, durable, and eflicient device by means of which a surgical or similar chair may be raised or lowered by rotating the chair and by means of which the chair can also be rotated without changing its height.

My invention consists in certain novel features and details of construction, all of which are described in the following specification and pointed out in the claims affixed thereto.

In the accompanying drawings, which illus trate one form of chair made in accordance with my invention, Figure 1 is a side elevation of the base and stem. Fig. 2 is a top plan view of a portion of the base. Fig. 3 is a section on the line 3 3 of Fig. 1. Fig. 4 is a section on the line 4 4 of Fig. 1. Fig. 5 is a top plan view of the chair-supporting member; and Fig. 6. is a side elevation, on a reduced scale, of the complete chair.

Like marks of reference refer to similar parts in the several views of the drawings.

The base consists of legs 10 and an internally-threaded sleeve 11. The legs 10 are also secured to the sleeve 11 by means of lagscrews 14, passing through projections 15 on the said leg portions 10. Within the sleeve 11 is a threaded stem 16. Carried in an opening 17 in the sleeve 11 is a friction'block 18, adapted to bear against the stem 16. The opening 17 and block 18 are made somewhat wedge shape in cross-section, as shown in Fig, 3, so that the block cannot drop out of position even when the stem 16 is removed from the sleeve 11.

19 is a short threaded rod which is carried Serial No. 153,902. (No model.)

by one of the leg portions 10 and adapted to bear against the friction-block 18. The rod 19 has pivoted to it a handle 20, by means of which it may be rotated. Secured'to the stem 16 by means of a pin 22, Fig. 4,is a disk 23. The upper end of the stem 16 enters an opening 24, Fig. 5, in the chair-supporting member 26. The stem 16 is provided with a rounded or conical upper end 27, upon which rests a bearing-block .28, secured to the chair-supporting member 26 by means of lag-screws 29. The chair-supporting member 26 is provided with a downwardly-projecting lug 32, in which is a threaded rod 33, adapted to bear against the periphery of the disk 23, and thus lock the chair-supporting member 26 against rotation independently of the stem 16. The rod 33 is provided with a handle 34, by means of which it is rotated. The chair-supporting member 26 is also provided with lugs 36, by means of which it is pivoted to the chair 37. The said member 26 is also provided with a number of arms 38. Between these arms 38 and the chair 37 are interposed suitable connections, by means of which the chair is adjusted. As the chair itself and these connections are of the usual form, they will not be described in detail.

In the operation of my chair the rod 19 is normally turned by means of handle 20, so as to force the friction-block 18 against the stem 16, and thus lock it against rotation in the sleeve 11. If the rod 33 is at the same time forced against the periphery of the disk 23, the chair cannot'be rotated. By turning the handle 34 the rod 33 may be moved out of contact with the disk 23 and the chair can then be freely rotated without altering its height. If, however, it is desired to change the height of the chair, the rod 33 is forced against the disk 23 and the rod 19 is loosened, so as to allow- I the stem 16 to rotate within the sleeve 11. If

pact and simple of construction it is very effective and completely within the control of the operator.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

1. In a surgical chair or the like, the combination with a base, of an internally-threaded sleeve carried thereby, a threaded stem within said sleeve, means for preventing rotation between said base and sleeve, a wedge-shaped opening in said sleeve, a wedge-shaped friction-block retained in said opening, and means carried by said base for forcing said frictionblock against said stem.

2. In a surgical chair or the like, the combination with a base composed of a'plurality of parts, of an internally-threaded sleeve, means .for clamping the parts of said base around said sleeve, a threaded stem within said sleeve, an' opening in said sleeve, a friction-block in said opening, mechanism carried by said base for forcing said friction-blockagainst said stem, and a chair-supporting member carried by said stem.

3. In a surgical chair or the like, the combination with a base composed of a plurality of parts, of an internally-threaded sleeve, means for clamping the parts of said base around said sleeve, a threaded stem within said sleeve, an opening in said sleeve, a wedgeshaped friction-block in said opening, mechanism carried by said base for forcing said friction-block against said stem, and a chairsupporting member carried by said stem.

4. In a surgical chair or the like, the combination with the base composed of two parts, of an internally-threaded sleeve, means for clamping the parts of said base around said sleeve, a threaded stem within said sleeve, an opening in said sleeve, a friction-block in said opening, a threaded member carried by said base for forcing said friction-block against said stem, and a chair-supporting member carried by said stem.

5. In a surgical chair or the like, the combination with a base composed of two parts, of an internally-threaded sleeve, means for clamping the parts of said base around said A. McDANNOLD.

Witnesses:

W. A. ALEXAN ER, JAMES H. BRYSON. 

